Apparatus and method for shredding wet chip materials

ABSTRACT

A shredder apparatus and method for shredding wet chip materials in which the shredder utilizes a shredder mechanism having a shaft attached to a frame, a bearing assembly disposed on the shaft, and a rotatable rotor disposed on the bearing assembly. First shredder members are attached to and rotatable with the rotor, and cooperate with second shredder members attached to the frame to shred wet chip materials fed into the shredder apparatus.

This application is a divisional of U.S. application Ser. No.10/611,526, filed on Jul. 1, 2003, now U.S. Pat. No. 7,028,935 which ishereby incorporated herein in its entirety.

FIELD

The method for shredding and the shredder apparatus disclosed hereinrelate generally to the shredding of wet chip materials thatsubsequently are separated into dry chips and fluid; and, morespecifically, to an improved shredder apparatus having a rotor shreddermechanism that allows for shredding of bales of stringy wet chip intogranular wet chips.

BACKGROUND

Bales or batches of wet chip materials often are generated in the courseof machining operations. The wet chip materials include both relativelysmall wet chips, referred to herein as granular wet chips, and stringypieces of wet chips. The chips are covered or coated with lubricating,cooling or other fluid. Additionally, undesired solids such as bolts,nuts, etc. sometimes are found in the bales or batches of wet chipmaterial.

Prior to sending wet chips to a centrifugal separator, where wet chipsare separated into dry chips and fluids, such as is illustrated inNemedi U.S. Pat. No. 5,106,487, the stringy wet chips generally must beshredded into granular wet chips. Otherwise, commercially-available wetchip separation systems sometimes will not function due to the largesize of the stringy wet chips. The wet chip material is fed into ashredder apparatus where the stringy wet chips are shredded intogranular wet chips that can be more readily transported in the wet chipseparation system free from interfering with the wet chip separationprocess or damaging the wet chip separation equipment.

Shredder apparatuses for shredding wet chip materials are well known inthe art. Often the shredder apparatus utilizes two rotatable shreddershafts each mounted in bearing units disposed in a shredder frame.Shredder members are disposed on each shaft, the rotating shreddermembers on one shaft cooperating with shredder members on the othershaft to shred wet chip material. Shredder apparatuses that employ aplurality of rotating shafts generally are relatively large, bulky unitsthat, because of their size, are not adaptable to certain applicationsthat have reduced space constraints.

In other applications, it is known to employ a wet chip shredderapparatus that utilizes a plurality of first shredder members disposedon a single rotatable shaft. A plurality of second shredder members isfixed to the shredder frame. In a shredding operation the first shreddermembers engage the second shredder members to shred wet chip material.An example of this type shredder is shown and disclosed in theco-pending application Ser. No. 10/100,786, filed by the presentinventor on Mar. 19, 2002. While this shredder device is satisfactoryfor shredding wet chip material, it has been observed that lubricatingand flume fluid can migrate to the location of bearing units that housethe rotatable shaft. A concern exists that, over time, the fluid couldpossibly contaminate or otherwise damage one or more of the bearingunits.

Further, it has been found in some applications that relatively heavyobjects such as metal bolts, nuts, etc. are located in the bales of wetchip material. In some instances, these heavy objects can cause theshredder to jam. On such occasions, the shredder device must be stoppeduntil the jam is cleared. In other situations, these heavy objects passthrough the shredder and travel in the system with the potential forcausing damage to a centrifugal wet chip separator or other parts of thewet chip separation system.

SUMMARY

Briefly, a shredder apparatus may have a shredder mechanism thatincludes a shaft attached to a shredder apparatus frame. A bearingassembly, comprising for example two spaced bearings, is disposed on theshaft and located inwardly from the shaft ends. A rotatable rotor,comprising for example an elongated cylindrical member, may bepositioned over the shaft and is disposed on the bearing assembly. Therotor may be of a length such that the rotor extends over the bearingassembly, whereby the bearing assembly is sandwiched between the shaftand rotor. Seal members may be disposed on the shaft and located at therotor ends serve to preclude lubricating, coolant or other fluid fromcoming in contact with the bearing assembly.

Spaced shredder wheels, each having a plurality of spaced shredder armsextending outwardly from the wheel, are attached to and rotatable withthe rotor. A plurality of spaced comb members is disposed on, but is notrotatable with, the rotor. The comb members are attached to the shredderassembly frame, whereby, upon rotation of the rotor, a shredder wheelwill cooperate with a comb member to shred wet chip materials intogranular wet chips.

In one embodiment, the shredder rotor is rotated in a direction oppositea feed direction of wet chip materials to be shredded. The shredder armson the shredder wheels contact wet chip materials, e.g., aluminum, steelor other metal chip materials, and lift the wet chip materials upwardlyinto the shredder. The shredder wheels and comb members then cooperateto shred the wet chip materials into granular wet chips that may be moreeasily transported through a wet chip separation system to one or morecentrifugal separators. During the course of the shredding operation,undesired heavy objects may drop either by gravity or centrifugal forceinto a removable tray attached to the shredder assembly frame, therebybeing separated from the wet chips.

In a further embodiment, the shredder rotor is rotated in the samedirection as the feed direction of the wet chip material to be shredded.The stringy wet chip material will shred at the location of a secondshredder arm on the comb member. In the event a heavy, unwanted objectcontacts the second shredder arm, an increased motor amperage will occurand the motor is signaled to change direction. The unwanted object willthen be lifted in the arms of the shredder wheels and ultimatelytransported to a drop out opening or tray. The motor will then changedirection again, and the shredding operation will resume principally atthe location of the second shredder arm.

To minimize potential shredder wheel misalignment problems thatsometimes occur with shredder apparatuses, spacers may be disposedbetween the shredder wheels. By separating the shredder wheels, thepossibility of a shredder wheel contacting another shredder wheel due tovertical misalignment is reduced.

Other advantages of such a shredder apparatus will become apparent fromthe drawings and the following detailed description of the shredderassembly and method of shredding.

DESCRIPTION OF THE DRAWINGS

FIG. 1 shows a front perspective view of an exemplary shredderapparatus, and provides a size comparison between the shredderapparatus, a five-gallon container and a one-gallon container;

FIG. 2 shows a rear perspective view of the shredder apparatus shown inFIG. 1 with the dropout tray removed from its normal position on theshredder frame;

FIG. 3 shows a plan view of the shredder apparatus shown in FIG. 1;

FIG. 4 shows a right side view of the shredder apparatus shown in FIG.1;

FIG. 5 shows a left side view of the shredder apparatus shown in FIG. 1with a portion of the shredder frame removed;

FIG. 6 shows a rear view of the shredder apparatus shown in FIG. 1 witha portion of the shredder frame removed;

FIG. 7 shows a section view taken along line 7—7 in FIG. 4;

FIG. 8 shows a side view of a shredder comb member employed in theembodiment illustrated in FIGS. 1–7;

FIG. 9 shows a left side view of a further embodiment of a shredderapparatus in which the comb members include first and second spacedarms, with a portion of the shredder frame removed;

FIG. 10 shows a side view of a shredder comb member employed in theembodiment illustrated in FIG. 9; and,

FIG. 11 shows a schematic block diagram of the drive assembly andcontroller assembly employed in the embodiment illustrated in FIG. 9.

DETAILED DESCRIPTION

An exemplary shredder apparatus 10 comprises housing assembly 11 that,as illustrated in FIGS. 4, 5 and 7, includes base 12, front wall 13,back or rear wall 14 and side walls 15, 16. Open top plate 17 is fixedat top plate ends 18, 19 and top plate sides 20, 21 to the appropriatehousing front, back and side walls.

Motor mount wall 22 extends upward from base 12 (FIG. 7). Wall 22 issubstantially parallel to and spaced from sidewall 16. Top wall 23,which can be made of either a rigid or flexible material, is removablyattached to walls 16, 22.

As illustrated in FIG. 7, drive assembly 30 includes motor 31 having ashaft 32 with a bushing 32 a keyed to the shaft. Screws 33, 34 extendthrough openings in motor flange 35 and openings 36, 37 in wall 22. Thescrews thread into tapped holes 38, 39 in motor mounting plate 39 a,which abuts wall 22. It has been found that a 460 Volt, three phase, 60Hz electric motor may be employed. It is appreciated that other sizemotors could be utilized by one of ordinary skill in the art.

Positioned below motor 31 is fixed shaft 40 which is greater in lengththan the distance between spaced sidewalls 15, 16. Elongated shaft 40 istapered for a portion at each shaft end 41, 42. Taper 43 extendsinwardly for a discrete distance from each shaft end. Taper 43 comprisesa first tier 44 and a second tier 45.

A bearing assembly comprising spaced bearings 50, 51 is seated on shaft40, each bearing being located on a tapered portion of shaft 40. In thisparticular embodiment illustrated in the drawings, bearings 50, 51 seaton shaft taper tier 45.

Cylindrical rotor 52 having an outer surface 53 and inner surface 54 ispositioned over fixed shaft 40. Rotor 52 is recessed at each rotor end55, 56 as illustrated, for example, in FIG. 7. Each bearing ispositioned so that it is sandwiched between shaft 40 and rotor 52.Bearing 50 is disposed within a rotor recess at rotor end 55 whilebearing 51 is disposed within a rotor recess at rotor end 56. A firstseal member 57 is disposed on shaft surface 45 at rotor end 56. A secondseal member 58 is located on shaft surface 45 at rotor end 55. The sealmember may be made of any conventional sealing material such aspolyvinyl chloride (PVC) or Buna N, so long as the material aids inproviding a seal at the location of the rotor ends.

Faceplate 60 is bolted at 62 to sidewall 16, while faceplate 63 isbolted at 64 to sidewall 15. Shaft end 41 extends through an opening infaceplate 60, and shaft end 42 extends through an opening in faceplate63. Faceplate 60 is located adjacent seal member 57, and faceplate 63 ispositioned adjacent seal member 58.

Lock member 65 is disposed on shaft 40 at shaft end 41 and seats againstfaceplate 60. Lock member 66 is disposed on shaft 40 at shaft end 42 andseats against faceplate 63. Each lock member is illustrated as beingwelded at 68 to a respective faceplate. If desired, other shaft lockingarrangements, for example, a two piece clamp trough, could be employed.Similarly, the shaft ends could be threaded and lock nuts could beutilized in place of the locking arrangement shown in the drawings. Withthe particular arrangement shown in the drawings, bearings 50 and 51 areplaced in a relatively closed or sealed location formed by shaft 40,rotor 52 and seal members 57, 58.

A first sprocket 70 is keyed at 71 to motor shaft 32 at the location ofbushing 32 a (FIG. 7). A second sprocket 72 is bolted at 73 to sprocketmounting plate 74, the latter being welded at 75 to rotor 52 at outerrotor surface 53. A drive chain, not shown, connects sprockets 70, 72whereupon activation of motor 31 and the sprocket chain assembly, rotor52 rotates on bearings 50, 51. Shaft 40 is fixed in place and does notrotate. Referring to FIG. 7, drive assembly 30 includes motor 31 and thesprocket chain assembly, the latter being enclosed by walls 16, 22 and23.

A plurality of spaced shredder wheels 80, each wheel including spacedshredder arms 81 extending outwardly from the wheel, is keyed atdifferent locations 82 to rotor 52. A plurality of spaced shredder combmembers 84, illustrated, for example, in FIGS. 5 and 8, is located onrotor 52, and is positioned so that a comb member 84 is adjacent ashredder wheel 80.

With reference to FIG. 8, each comb member 84 includes a comb portion 85and a comb arm 86. Opening 87 is formed in comb portion 85, while a keyslot 88 is formed at the outboard end of comb arm 86. Each comb memberis adapted to be inserted on rotor 52, and seats on the rotor at thelocation of comb opening 87; however, the comb members do not rotatewith rotor 52. End comb member is keyed at the location of slot 88 tokey bracket 89, the later being fixed to rear wall 14, as seen in FIG.5. Accordingly, shredder wheels 80 rotate relative to fixed adjacentcomb members 84 and together, the shredder wheels and comb memberscooperate to shred or otherwise cut wet chip material passing throughshredder apparatus 10.

Spacers, in the form of washer-like members 90, are disposed on rotor 52and positioned between adjacent comb members 84, as shown in FIG. 7. Thespacers 90 serve to space the shredder wheels 80 apart so that, shouldany vertical misalignment of a shredder wheel 80 occur, the spacer 90will preclude contact with another shredder wheel 80.

Compression spring assembly 92 formed of compression spring 93 andspring plate 94 is positioned against the outboard surface of combmember 84 located near one end 56 of rotor 52. Compression springassembly 96 formed of compression spring 97 and spring plate 98 ispositioned against the outboard surface of comb member 84 near theopposite rotor end 55.

A heavy object dropout tray or box 100 is removably attached to theouter surface of rear wall 14 in a manner well known to a person ofordinary skill in the art.

In operation, wet chip materials to be shredded comprising granular wetchips, stringy wet chips, unwanted solids (such as bolts, nuts, etc.)and lubricating, cooling, flume or other fluid are delivered to theopening 101 in the front wall 13 of shredder 10. The wet chip materialmoves into the shredder traveling in the direction shown by arrow “A”(FIG. 4). Upon actuation of drive assembly 30, rotor 52 rotates andtravels in a direction, shown by arrow “B,” opposite to the direction ofwet chip material travel. As the wet chip material passes into shredder10, shredder arms 81 on shredder wheels 80 engage the material and causeat least the stringy wet chip material to be lifted upwardly in thedirection of arrow “B” toward a shredding station.

At the shredding station, shredder wheels 80 and shredder comb members84 engage and cooperate to shred the stringy wet chip material andreduce it to granular wet chips. As rotor 52 continues to rotate,shredded granular wet chips drop to the bottom of shredder 10. Unwantedsolids in the form of nuts, bolts and the like which may have beenlodged or otherwise entrained in the stringy wet chip material to beshredded either drop out of the material or are thrown by centrifugalforce into collection tray 100. The shredded wet chips now reduced to adesired size then can be processed out of shredder apparatus 10 at theopening 102 in rear wall 14 in a centrifugal separation system wherebythe wet chips are separated into dry chips and fluid.

Shredder apparatus 10 can be made of a reduced size such as illustratedin FIG. 1, where shredder apparatus 10 is shown compared in size to afive-gallon container and a one-gallon container. One particularshredder apparatus 10, for example, has a width of 16¼inches, a depth of19 inches, and a height of 26 inches. A reduced-size shredder apparatusis particularly desirable in those applications where there is a spaceconstraint.

Additionally, the use of spacer washers 90 serve to minimize shredderwheel alignment problems because the shredder wheels 80 have been spaceda satisfactory distance from one another.

A further embodiment of a shredder apparatus 10 is illustrated in FIGS.9–11. In this particular embodiment, comb members 103 replace combmembers 84. Each comb member 103 includes base portion 104, and a firstarm 105 and a second, spaced arm 106 extending outwardly from baseportion 104.

An opening 107 is formed in base portion 104, while a key slot 108 isformed at the outboard end of comb arm 105. Comb arm 106 preferably isserrated at 109 along substantially the length of one side 110 of combarm 106.

Each comb member 103 is adapted to be inserted on rotor 52 and seats onthe rotor 52 at the location of comb opening 107; however, comb members103 do not rotate with rotor 52. Each comb member 103 is keyed at thelocation of slot 108 to key bracket 89, the later being fixed to rearwall 14, as seen in FIG. 9.

In addition to replacing the comb members 84 with the comb members 103,shredder wheels 80 are replaced with shredder wheels 116. Wheels 116each include spaced shredder arms 118 extending outwardly from thecenter of wheel 116. Each shredder arm 118 has sides 120, 121 formed orgrooved inwardly at 122 to define a concave surface, as illustrated inFIG. 9. Accordingly, in this embodiment, shredder wheels 116 rotaterelative to fixed adjacent comb members 103, and together the shredderwheels 116 and comb members 103 cooperate to shred or cut wet chipmaterials at the locations of comb arms 105 and 106.

In particular, during the operation of the embodiment of the shredderapparatus 10 of FIG. 9, wet chip materials to be shredded, comprisinggranular wet chips, stringy wet chips, unwanted solids (such as bolts,nuts, etc.), and lubricating, cooling, flume or other fluid, aredelivered to the opening 101 in the front wall 13 of shredder apparatus10. The wet chip material moves into the shredder apparatus 10 travelingin the direction shown by the arrow “D” in FIG. 9.

Upon actuation of drive assembly 30, rotor 52 rotates and travels in adirection, represented by an arrow “E” in FIG. 9, that is the samedirection as the direction of the wet chip material travel. As the wetchip material passes into shredder 10, shredder arms 118 engage the wetchip materials and direct at least the stringy wet chips toward ashredding station disposed at comb arm 106. Comb arms 106 and shredderarms 118 cooperate to shred the stringy wet chips.

In the event that a heavy, unwanted solid enters shredder apparatus 10,the solid travels to the shredder station disposed at the comb arm 106.Inasmuch as the shredder apparatus 10 cannot shred the unwanted solid,an increase in the motor amperage occurs, whereupon the motor 31 stopsand changes direction of rotation. With the change in the direction ofrotation of the motor 31 (and in particular motor shaft 32), rotor 52will change its direction of rotation, and the shredder wheels 116,fixed to the rotor 52, will the rotate in the direction indicated byarrow “F” in FIG. 9. As the shredder wheels 116 rotate in the directionof arrow “F”, the unwanted solid will be carried on one or more surfaces122 on the shredder arm 118, and transported in the direction of arrow“F”. The unwanted solid may be transported in somewhat of a circulardirection until the unwanted solid, for example, drops onto the top offirst comb arm 105 and passes therealong into drop out tray 100. Afterrotor 52 travels in the direction of arrow “F” for a period of time, forexample, until at least the unwanted solid passes into tray 100, themotor 31 again changes direction and rotor 52 travels in the directionof arrow “E”, whereupon shredding of the wet chip material resumes.

FIG. 11 illustrates a controller system 128 associated with theembodiment of the shredder apparatus 10 in FIG. 9. The controller system128 includes a controller 130. When controller 130 is turned to an “on”position, the controller 130 closes forward switch 131 and actuatesmotor 31, which causes motor shaft 32 to rotate in the direction ofarrow “E”.

Upon contact of an unwanted solid with comb arm 106, increased amperageoccurs in motor 31 and is sensed by sensor 132. The controller 130receives signals from the sensor 132 representative of the increasedamperage, and, in response, turns off motor 31 and opens forward switch131 to a disconnect position. Following a dwell period of, for example,approximately one second, the controller 130 closes reverse switch 133and actuates motor 31, causing motor shaft 32 to rotate in the directionof arrow “F”.

Following a time period during which an unwanted solid is transported tothe top of comb arm 105, the controller 130 turns off motor 31 and opensreverse switch 133. Following a dwell period of, for example,approximately one second, the controller closes forward switch 131 andactuates motor 31, whereupon motor shaft 32 again rotates in thedirection of arrow “E” and shredding occurs at the location of shredderarm 106.

It is appreciated that while one system 128 for actuating motor 31 topermit shaft rotation in the direction of arrows “E” and “F” has beenshown, other systems for rotating motor shaft 32 in the desireddirections would be apparent to one of ordinary skill in the art. Forexample, rather than using the controller 130 to control the motor 31 tomake motor shaft 32 rotate in a particular direction for a particularamount of time, the controller may control the motor 31 to make themotor shaft rotate in a particular direction for a particular number ofrevolutions or over a particular angular distance.

While the bales of stringy wet chips are shredded principally at theshredder stations at the second comb arms 106 in the embodiment of FIGS.9–11, shredding can also occur at the location of the first comb arms105 during the course of the unwanted solid removal.

Similarly, while comb arm 106 has been shown to have a serratedshredding or cutting surface 109 along side 110, it may be that, in someapplications, serrations are not required. Accordingly, a person ofordinary skill in the art could select other shapes for the sides 110,for example, a smooth surface.

While the shredder apparatus 10 has been shown standing alone, it isappreciated the shredder apparatus 10 could be employed in a flume,where bales of stringy wet chip material, granular wet chips andunwanted solids are transported in a fluid to the shredder apparatus 10.Shredder wheels 80, each with its respective shredder arms 81, wouldengage and lift the stringy wet chip material upward, at least partiallyout of the flume, and then shred the material. An example of the use ofa shredder apparatus employed in a flume application is shown anddisclosed in the co-pending application Ser. No. 10/100,876, filed bythe present inventor on Mar. 19, 2002, the disclosure and claims ofwhich are incorporated herein by reference.

While one or more embodiments have been illustrated and described indetail herein, it will be understood that modifications and variationsthereof may be effected without departing from the spirit of theinvention and the appended claims.

1. The method of shredding wet chip materials into granular wet chipswith a shredder apparatus comprising: a frame; a shaft attached to saidframe, said shaft having a length and a first end and a second end; abearing assembly disposed on said shaft and located inwardly from saidshaft ends; a rotatable cylindrical shaped rotor having a first end andsecond end and a length less than said shaft length, said rotor beingdisposed on said bearing assembly; a plurality of spaced first shreddermembers attached to said rotatable with said rotor; a plurality ofspaced second shredder members attached to said frame, said secondshredder members being positioned relative to said first shreddermembers whereby a first shredder member and a second shredder member areadapted to cooperate to shred wet chips; and, a drive assembly forrotating said rotor while said shaft remains in a fixed position wherebyupon actuation of said drive assembly, said rotor will rotate causingsaid first and second shredder members to cooperate to shred wet chipmaterial in said shredder apparatus; said method including the steps of:directing wet chip materials to be shredded in a first direction towardsaid shredder apparatus; rotating said rotor in a direction oppositesaid first direction whereby said first shredder members contact saidwet chip materials to be shredded and lift said wet chip materialupward; and, delivering said wet chip material to a shredder locationwhere said first and second shredder members engage and cooperate toshred said wet chip material.
 2. The method of claim 1 and furtherincluding the step of allowing shredded wet chips to fall by gravitytoward the bottom of said shredder apparatus.
 3. The method of claim 2and further including the step of removing solid objects from saidshredder during the course of shredding wet chip material.
 4. The methodof claim 1 and further including the step of removing solid objects fromsaid shredder during the course of shredding wet chip material.
 5. Themethod of claim 1 wherein said first shredder members each comprise ashredder wheel having a plurality of spaced shredder arms and saidshredder arms engage the wet chip material to be shredded.
 6. The methodof claim 1 and further includes the step of rotating the rotor over theshaft.
 7. The method of shredding wet chip materials into granular wetchips with a shredder apparatus comprising: a frame; an elongated shaftmember attached to said frame, said shaft having a length and a firstend and a second end; a bearing assembly disposed on said shaft andlocated inwardly from said shaft ends; a rotatable cylindrical shapedrotor having a first end and second end and a length less than saidshaft length, said rotor being disposed on said bearing assembly; aplurality of spaced first shredder members attached to and rotatablewith said rotor; a plurality of spaced second shredder members attachedto said frame, said second shredder members each having spaced combshredding arm and being positioned relative to said first shreddermembers whereby a first shredder member and a second shredder member areadapted to cooperate to shred wet chips; and, a drive assembly forrotating said rotor while said shaft remains in a fixed position wherebyupon actuation of said drive assembly, said rotor will rotate causingsaid first and second shredder members to cooperate to shred wet chipmaterial in said shredder apparatus; said method including the steps of:directing wet chip materials to be shredded in a first direction towardsaid shredder apparatus; rotating said rotor to travel in the samedirection as the wet chip material to be separated, and, delivering saidwet chip material to a shredder location where said first and secondshredder members engage and cooperate to shred said wet chip material.8. The method of claim 7 and further including the step of reversingsaid rotor rotation thereby causing said first shredder members totravel in a second direction for a discrete distance.
 9. The method ofclaim 8 and further including the step of again reversing said rotorrotation thereby allowing said first shredding members to travel in saidfirst direction.
 10. The method of claim 7 in which said drive assemblyis actuated to change rotor directions upon an unwanted heavy objectcontacting said second shredding member arm when said wet chip materialis traveling in said first direction.
 11. The method of claim 7 andfurther including the step of removing solid objects from said shredderduring the course of shredding wet chip material.